Process of treating carbon or carbonaceous compounds



March 2l, '1939. Ef sLATlNEANU l 2,151,165

PROCESS OI"I TREATING CARBON OR CARBONACEOUS COMPOUNDS Filed April 18,1936 gas coma/@725er Patented Mar. 2l, 1939 UNITED STATES PROCESS FTBEATING CARBON 0B CARBONAUEOUS COMPOUNDS Eulalnpin Slatineanu,Oberhausen, Germany, as-

signor to Gewerkschaft Auguste, Oberhausen,

Germany, acomlnny of Application April 18,. In Germany l5 Claims.

My invention relates to the heat treatment of carbon and carboncompounds, including the hydrogen and oxygen compounds, for theproduction of valuable products of various kinds.

It is an object of my invention to produce valuable products and moreespecially hydrocarbons from carbonaceous materials such as carbon, forinstance coal, or carbon compounds, including saturated and unsaturatedhydrocarbons, which at room temperature may be solid or liquid orgaseous.

It is a particular object of my invention to produce valuablehydrocarbons, starting from coal of any provenience, such as mineralcoal or l5 brown-coal or charcoal or lignite, or peat, or from coaldistillation products such as tar, or from other natural carbonaceousmineral deposits and their products such as mineral oils or any naturalor articial mixture of such substances. Under the collectivedenomination "mineral o I summarize in the rst line petroleum, liquidcondensates from natural gas, liquid or unguentous distillates orresidues from petroleum, mineral wax or natural asphalt, in the secondline distillates from brown-coal, bituminous slate, peat and mineralcoal (crude tar).

,My invention relates more particularly to the production of valuablecompounds from carbonaceous materials by the action, at an elevatedtemperature and under high pressure, of methane.

The drawing ailixed to the present speclcation and forming part thereofis a diagram illustrating by way of example the manner in which myinvention may be carried out.

My invention is based -on 'the discovery that the methane molecule. incontrast to all that could be expected, when acted upon by highpressure, is no longer an indiiferent, but a highly reactive compound. Ihave ascertained that under the action of high pressure the methane willnot only prevent CH4 from being split off the compounds treated, butwill even cause (l1-I4` to combine with the starting material or withthe fragments, into which these materials were split. In certain cases acondensation occurs simultaneously. These reactions may be accompaniedby a splitting up of carbon chains of the starting material.

The pressure required in the new processammmtsasaruletooatmospheresasaminimum. If, however, ethylene and/oracetylene are vpresentin the gas mixture in a quantity amounting toabout 20 per cent or more by volume, a pressure of about 250 atmospheresmay be suiilcient to render the methane highly reactive in the senseexplained above. In. many caseslprefertochoosethepartialpressure ofthemethanefarhigherthanthesumofthepar- 1936. serial No. '15,250 Aprilze, 1935 tial pressures of the gaseous compounds reacted with it.

The present invention is based on the idea that the dipol-free moleculesof CHl are polarized, when acted upon by high pressure, i. e. when the 5electron shells are compressed.

In contradistinction to prior art processes a reaction temperature of390 C. need not be overstepped, whereby the control of the operation isfacilitated and the apparatus rendered simpler and less expensive.

The temperature limit, above which the desired reactions do not proceedany more with satisfactory yield, can be determined by means of thethermodynamic formulae of the free energies calculated for instanceaccording to the method of Lewis and Randall. In certain cases, dened bythe well knownphase rule, the same is true of the limits of themolecular proportions of. the reacting materials. I have found itadvantageous as far as the yield is concerned, to determine the reactiontemperature and the molecular proportions in such manner that the valuesof the free energies of the reactions intended to take place (ifexpressed according to Lewis and Randall remain within the range of a:and +5000 gcal. (gram-calories), wherein a: is a value, expressed ingcal., which must be less than +5000 gcal., no matter whetherY it ispositive or negative. At a predetermined temperature the free energiesare always equal to the expression:

-RT zn K=QF (l2 here stands for A).

and +5000 seal.

If R is the gas constant, T the absolute temperature, ln Napierslogarithms, K the equilibrium constant, the formula, if Briggs logarithmis used, will be f 4.5753 TlOg K=QF. From the constant K the totalpressure Acan be computed according to the law of mass action as the sumof the partial pressures of the components of the equilibrium.

From the formula there thus results that the partial pressures of thecomponents formed and v simultaneously the yield rise, as the partialpressure oi the methane rises. The rising pressure of the methane alsofavors the conversion of the free carbon, which may be present, into anonsolid phase.

The reaction may also be furthered and accelerated by adding suitablecatalysts; however, in'view of the high pressure the presence ofcatalysts is not necessary.

If this process is for instance applied to high molecular weightparafine hydrocarbons, methane will combine with lower molecular weightc' DF corresponds to ailgure ranging between :c 5 4' fragments resultingfrom the splitting of the carbon chain. In the case of unsaturatedhydrocarbons mainly a combination of methane takes place, accompanied bycondensation. However, the reaction may also be so conducted that at thesame time the starting material is split vup into lower molecular weightcompounds.

Aromatic polycyclic compounds such as naphthalene, anthracene etc. canbe converted under the inuence of methane into lower molecular widesttechnical application. 1

Instead of methane also gas mixtures containing methane may be used;obviously the partial pressure of the methane in the system must be keptcorrespondingly high.

If the methane or the gas mixture containing same also contains about20% by volume of more ethylene or acetylene, the operation may also becarried through' under a pressure of less than 500 and sometimes evendown to 250 atmospheres. For similarly as carbon monoxide (CO) suchunsaturated hydrocarbons are unstable molecules and the reaction istherefore not only stimulated by the pressure, but also by the potentialenergy of the unsaturated molecules.

In many cases it has been found advantageous to cause the reaction totake place in the heterogeneous system, i. e. in such manner that atleast one of the reaction components already present or the finalproducts formed remains liquid under the operating pressure.

The cleavage products (fragments) such as methane and its'homologues,hydrogen, ethylene and its homologues, carbon monoxide, acetylene andits homologues, naphthalene, other tar constituents and solid carbon,which are formed in the hitherto known processes of conversion ofcarbonaceous materials, are not stable under the conditions of operationof the present process, but will react according to the followingequations with the formation of liquid hydrocarbons:

In these equations only representatives of the different groups(paraflines, olenes, acetylene, naphthenes, naphthalene's, etc.) areshown. The reactions will occur in a similar manner with 2CO=CO1+C Ifthe gaseous phase contains hydrogen, equilibrium the . CO+H2=H2O+C mayalso play a rle.

Under the operating conditions the carbon thus separated will react withthe higher molecular I carbon compounds and also with the methane.

If carbon monoxide and hydrogen are present, the new process may alsoAbe explained thermooccurs and that thereafter the alcohol reacts withhigher molecular organic carbon compounds dynamically in such mannerthat primarily the and/or with methane for instance according to the A'These theoretical considerations were subjected to practical laboratorytests and it was found that under' the conditions of this invention,alcohols of any kind will in fact react with higher molecular organiccanbon compounds and/or with methane for instance as follows Unsaturatedhydrocarbons also have the tendency of separating carbon from thegaseous phase, for instance as follows:

In view of thermodynamic calculations the reaction between carbonmonoxide and methane may also proceed byvway of ethylene as follows:

The ethylene will then however be decomposed.

again according tothe equation (a). Consequently in this or similarreactions special provision must be madel for preventing the separationof carbon.

This separation can be prevented by the following steps:

(1) I'he partial pressure' of the methane must exceed by farthe partialpressure of the gaseous component to be reacted with methane, and/or Y(2) The reactions must proceed in a system which under the conditions ofoperation contains at least one liquid-phase. This liquid phase may beadded under the form of a suitable hydrocarbon, for instance paraflineoil.

For thermodynamic reasons carbon does not react with methane directlyfrom a solid phase.

The manner in which the conditions of reaction are calculated may beillustrated for the example:

'I'he value for P F is calculated as follows :l Since EF represents thevalue for the free energies, all components (heat of formation,rspecicheat, heat of vaporization etc.) have been considered therein, so thatin contrast to the usual state-- ment of the mere heat tone of areaction, here the true excess of energy of the reaction is brought out.

The heat of formation (Dfi) of methane from graphite (C) andhydrogen-(Ha) amounts at 291 absolute (18 C.) =l8 300 gcal.

The value of the specific heat Cp for methane is equal to zsm-00231T-aooo 0042 T2 goal.

for Hz the specific heat is equal to C,=6.65+0.000'I T and for graphiteis equal to C,=1.1+0. 0048 T0.000 0012 T2 If according to the equationC+2Hz-CH4 the algebraic sum of (1), (2) and (3) is computed, thereresult The heat of formation of CH4 from its elements at absolute thenis Hm=Ho-11.83 T+ Consequently DH0=15 500 gcal.

From the equilibrium measurements of Lewis and Randall results theintegration constant of the reaction isochore is Areplaced by Brlggslogarithm, the formula reads:

D=15 500+2724 T log T-0.00845 T2+ 0.000 005 T352.07 T ('I) )From thisformula the column a of schedule 1 has been calculated.

If in a similar manner the free energy of the formation of acetylenefrom its elements according to the equation is ascertained, thereresults the following formula:

(The integration constant of the reaction isochore was assumedempirically as J =-65) QF==17.680+11.1 T ln T-0.0055 T265 T DF=170a0+25.56 riog T-aooss'ra-ss T Column b of schedule 1 was computedaccording to this formula.

In the case of octane the following calculation results The specificheat for the liquid 'CsHia (at 25 C.) is 0.5052, the molar heat capacity(3:57.66. 'I'he specific heat of the parafllne series in the liquid andsona phases is proportional to the absolute temperature, thus for CaHnThe entropy of melting is (The heat of solution of paramne-wax inpetroleum distillates is 40.3 cal. per gram, which is identical with theheat of melting and must be independent from the molecular weight.)

The complete entropy for liquid CsHu at 25 The heat of combustion ofCama is 1 300 700 goal. per gram/molecule.

i The algebraic sum ofthe heat of combustion of the components and ofoctane result in the heat of formation f Hm: -68 000 gale. 'I'he freeenergy therefore is nF,= 1 H-r1 s= -9 `300 The vapor pressure of 03H1:at 25 C. is 15.4 mm. The free energy of the vaporization of one moleculegaseous 00H1: is according to the following formula P QF.- -RTIn =+2 300At ordinary temperatures the heat capacity of liquid Cama la:

QC,= 58.6+ 0.122 T l ?Hn|=1 H.-I58.6 T+0.061 T3= -68 000 This results inv Hm= 69.65 (at the absolute boiling point) For liquid octane formedfrom its elements the equation for the free energy up to here reads asfollows:

QF= ,-ss 000+sa6 r 1n T o om 12-159.: r or expressed in Briggslogarithms:

9F= -ss 000+ 134.93 r 10g T-0.061 12 -1s9.2 T

gpm: 19 200 (for the liquid as well as for the vapor phase) The specificheat of CnHra vapor has never been published. It can be computed asfollows:

'Ihe latent heat of vaporization is QH,=8060 galcJg. mol at 125C.(boiling point) For hexane the latent heat of vaporization amounts to6820 at 70 C. and to 7680 at 0 C.

Assuming that the increase of QH' at dropping temperature is the samewith hexane and octane, Q Hv at 25 C. may be estimated as 9500 gcal.

The total heat capacity of the C0111 vapor be-A tween 25 C. and 125 C.amounts, similarly as that of the liquid octane within this range oftemperatures, to plus DHV at 125 C., minus QH' at 25 C. and with acorrection for the Joule- Thomson-eect at 2 5? C. (=70 goal).

(111er C.)C,=%0==48.32

c,=3s.+ 0.0383 T From (2), (3) and the last formula result:

gH=gH-33.5 1'

2H15=1 JH,59 5s0= -51 500 gen1.

The free energy of the reaction-equation 8C+9H2= CsHis (8a3 Phe) nowreads in all QF=48 200+33.6 T In T- 53.4 T or when using decadiclogarithm QF= -48 200+77.367 I'log T- 53.4 T

This formula was used in computing the column c for octane.

The free energy of the reaction 7C2H4+2CH4=2C3H15 can now be computedfrom the schedule 1 by way of the algebraic sum (7b-+2a)+2c=d Forexample for the temperature T=640 absolute (367 C.) as follows:

Under the equation previously deducted:

gri-4.5153 1' 15g K=1a 51s K is then computed as follows:

may be explained.

From the computation of the free -.energy and heat of formation resultsthe free energy of the total reaction 1 F= 104 S60-92.68 TlnT+ l 0.11813-0. 00309 Tiki-600.11 T or 13112:-104 s60-213.4 115g 1+ A The freeenergies for the temperature ranges to be lnvestlgatedare According tothe equation 9r= 111' m K= 31.230556 1' 15g K Schedule grew-RT 1n11p-4.5153111551:

a b c d' 151 450 1821 11 921 +B 010.5 -55 395 v1101 430 -1321 1s 1055+25 139.3 -00 521 341 520 3151.5 +19 51o +52 514.3 13 sas As basis forthe computation of the thirteen type-.reactions shown on page 2 thefollowing formulae for the free energies of the starting materials weregru- 04 no4-0.50 11111-00055 11+ the several temperatures are computedas follows: l

,T abs. Log K 5m 27. 725023 550 24.246757 l0 2l. 203025 550 18. 7355747m l5. 481498 DFJ- f-ua e30-92.19 r1nT+0.12015 T2- .0.00000359Thi-519.18 1' "either o f the starting materials or of the productsformed in the reaction-shall be liquid under the conditions of reactin.In the reactions mentioned abovewater will always appear as a component,since the plurality of these reactions proceed below the critical pointof water, and therefore the liquid phase is here already present underthe form of water. One may however also provide the liquid'phase byinjecting into the reaction chamber, besides the reaction components tobe reacted in the iirst place. also substances which remain liquid underthe reaction conditions, such as for instance paraillnes, paramne oil,vaselines, tar oils, etc. This addition is particularly useful in thecase of reaction components having a tendency to separate out lowmolecular paraiiines. In such case heavier paraiilnes added to themixture will react with the light paraillnes formed and will act towardscarrying the reaction to completion within a technically admissibleperiod of reaction.

The values for the free energies used in the examples of calculationgiven above are calculated for water vapor. In relation to liquid waterthe figures in goal must be reduced correspondingly.

The following are some examples illustrating the basic reactions:

1. 7CH2=CH.CH2OH (allyl alcohol) +11CH4= 4CaH1s+7HzO V2. (CzHs) :COH(triethyl carbinol) +CH4= CsHis -l-HzO 4. CcHsOH (phenol) V+CH4=` CEaCH:(toluene) -l-HrO 5.A cartomancia:

camera), mylene) +2mo In the drawing I is an autoclave provided with anelectric heater 2. 3 is a catalyst or contact liquids, while I is a pumpserving to keep the products circulating in the way shown by arrows. Inpractising this invention 4one may proceed for instance as follows:`

Example 1 In an autoclave such as used for instance in a hydrogenationprocess, 100 kg. parafflne oil per hour were treated at 350 C. under apressure of about 1000 atm. with methane, the 100 kg. paralne oil beingthequantity which passed hourly through the apparatus. The catalystpresent was composed of copper iodide, molybdenic acid and magnesiumoxide. The hourly yield was 112 kg. benzines, about 80% of which wereoctane. Ihe reaction thus proceeded substantially according to theformula The paramne oil ,was treated not with pure methane` but with agas mixture containing besides methane about 30% hydrogen. The pressurewas here raised to about 1500 atm. The percentage of yield was about thesame asin Example 1.

y Example 3 In the autoclave 100 kg. naphthaline were treated hourly at330 C. and under a pressure of about 2000 atm. with methane in theabsence of any catalyst, kg. parafllne oil being however injected per100 kg. naphthaline. The hourly yield was 65 kg. benzene and toluene and99 kg. benzine, mostly octane.

Example 4 A gas mixture containing 40% by volume C0 and 60% by volumeCH4 was reacted at 260 to 280 C. under,a pressure of about 1000 atm. ina reaction chamber, the space available for the catalytical reactionamounted to about 30 liters and was filled with an iron-molybdenumcatalyst. 30 cbm. oi the gas mixture were reacted per hour and 5.3 kg.parafline oil (boiling at about 360 C.) were injected per hour, Theyield was 13.9 kg.=19.7 liters of a benzine, 93% of which boiled below150 C. and which was free from unsaturated compounds. When thetemperature was raised to 285 to 318 C., liquid oleilnes and naphtheneswere formed.

Example '5 A gas mixture of 7 cbm; H, 7 cbm. CO and 21 cbm. CH4 wasreacted at 184 to 224 C. under about 1000 atm. pressure in a reactionspace of about 30 liters in the presence of a tungsten-iron catalyst.ASince here a liquid phase (water) was present, no'paraillne oil or thelike need be injected. The hourly yield was 10.3 kg.=15.5 litersbenzine, 95% of which boiled below 170 C. Be-

sides this 6 liters water were formed.

Example 6 Example 7 A gas mixture consisting of 4.7 cbm. ethylene I and14.1 cbm. methane was reacted at 260 to 320 C. under 400 atm. pressure,the catalyst space of 20 liters containing an iron-molybdenum-sodiumbromide catalyst. 4.8 kg. parafline oil were injected per hour. Thehourly yield was 15.4 kg.=-21.9 liters benzine, 90% of which boiledbelow 170 C.

Example 8 11.5 kg. liquid parailine and 4.25 kg. parailine oil werepassed per hour into the catalyst space of 20 liters volume containingan iron-molybdenum catalyst. The apparatus was kept under a pressure of760 atm. by forcing in per hour a mixture of 2.5 kg.=2 cbm. ethylene and6.7 cbm. methane. The temperature was kept at 180 to 260 C. There wereobtained 14.8 kg. aromatic hydrocarbons mainly benzene and toluene and3.0 kg. parafline, mainly octane.

Eample 9 Under the conditions described with reference to Example 8 andtogether with the paramne oil 1 kg. finely ground mineral coal wasinjected per hour, however instead of 2 cbm. 6.7 cbm. ethylene wereforced in per hour. There were obtained 14.6 kg. aromatic hydrocarbons,mainly benzene and toluene, and 12.7 kg. benzine, mainly octane. Theprocess may be carried through in an apparatus of the kind used for highpressure reactions, for instance in a hydrogenation apparatus as used inthe Bergius-process.

Various changes may be made in the details disclosed in the foregoingspeciiication without departing from the invention or sacricing theadvantages thereof.

I claim: l

1. The process of producing hydrocarbons from 'between 180 and 390 C.with a gas mixture,

which contains a substantial proportion of methane, under so high apressure that the partial pressure of the methane amounts to at least500 atmospheres.

3. The process oi.' vclaim 2 in which coal of any kind is treated withmethane in the presence of at least one liquid phase which is physicallyconstant under the conditions of reaction.

4. The process of claim 2 in which natural bitumen is treated withmethane in the presence of at least one liquid phase which is physicallyconstant under the'conditions of reaction.

5. The process of claim 2, in which asphalt is treated with methane inthe presence of at least one liquid phase which is physically constantunder the conditions of reaction.

`6. The process of claim 2 in which a mixture of bitumen and asphalt istreated with methane in the presence of at least one liquid phase whichis physically pstant under the conditions of react on.

7. The process of claim 2 in which a mineral oil is treated with methanein the presence of at least one liquid phase which is physicallyconstant under the conditions of reaction.

8.' The process of claim 2 in which a tar is treated with methane in thepresence of at least one liquid phase which is physically constant underthe conditions of reaction.

9. The process of claim 1, in which the treatment is effected in aheterogeneousl system, at

- least one liquid phase participating in the reaction.

10. The process of claim 1, in which the treatment is effected in aheterogeneous system, at

least one liquid phase being formed by an added' v from othercarbonaceous materials, which comprises acting upon such material at anelevated temperature not exceeding 390 C. with a gas mixture, whichcontains a material proportion voi? methane and more than 20 per cent byvolume ethylene, under a totalpressure oi.' at least 250 atmospheres andunder a partial pressure of methane which suiiices to cause apolarization ofthe methane present.

14: The process of. producing hydrocarbons from other carbonaceousmaterials, which comprises acting upon such material at an elevatedtemperature not exceeding 390 C. with a gas mixture, which contains amaterial proportion of methane and more than 20 per cent by volumeacetylene, under a total pressure of at least 250 atmospheres andunder'a partial pressure of methane which.suices to cause a polarizationof the methane present.

15. The process o! producing hydrocarbons from other carbonaceousmaterials, which comprises acting upon such material at an elevatedtemperature not exceeding 390 C. with a gas mixture, which contains amaterial proportion oi.' methane and more .than 20 per cent by volumeethylene and acetylene, under a total pressure o! at least 250atmospheres and under a partial pressure of methane which sumces tocause a methane present.

